1. Field of the Invention
This invention relates to a liquid supply apparatus preferred when used in a printing press, which can perform rotary screen printing or coating, or in a coating machine.
2. Description of the Related Art
Among existing printing presses capable of rotary screen printing are those disclosed, for example, in Japanese Unexamined Patent Publication No. 1999-188852 (hereinafter referred to as Patent Document 1) and Japanese Unexamined Patent Publication No. 2000-127351 (hereinafter referred to as Patent Document 2).
The printing press disclosed in Patent Document 1 includes an impression cylinder, an intaglio cylinder in contact with the impression cylinder, a blanket cylinder in contact with the intaglio cylinder, a plurality of pattern rollers in contact with the blanket cylinder, a plurality of first ink supply means for supplying inks to the pattern rollers, and a second ink supply means for supplying ink to the blanket cylinder with the use of a rotary screen. In Examples of Patent Document 1, the rotary screen contacts the blanket cylinder via a rubber roller.
The printing press disclosed in Patent Document 2 is an intaglio printing press including a plate cylinder having an intaglio mounted on a circumferential surface thereof, an impression cylinder in contact with the plate cylinder, an ink collecting cylinder in contact with the plate cylinder and having a blanket mounted on a circumferential surface thereof, a first ink supply means for supplying ink to the blanket of the ink collecting cylinder, a second ink supply means in contact with the plate cylinder for supplying ink to the intaglio, and a wiping roller in contact with the plate cylinder, the second ink supply means being furnished with a rotary screen. In Examples of Patent Document 2, the rotary screen contacts the plate cylinder via a rubber roller.
In the printing presses disclosed in Patent Document 1 and Patent Document 2, however, rotary screen printing is carried out, with the rotary screen being located below the rubber roller to feed ink upwardly of the screen. Thus, it cannot be expected for ink, which has been scraped off by a squeegee, to fall reliably onto a pattern forming portion (a small hole group) of the screen. This has posed the problem that an adequate amount of ink fails to be supplied to the pattern forming portion, thereby causing nonuniformity in printing, and inducing an increased waste of paper.
The present invention has been accomplished in light of the above-described problem. The invention provides a liquid supply apparatus which can continuously supply an adequate amount of liquid to the small hole group in the plate material.